Perhaps you should try some spelling variations:
"a robust _. hellman book" » "a robust _. hellman joel", "_ robust _. hellman book"
"a robert e. heilman book" » "gal robert e. heilman book", "a robert _. heilman book", "a robert e. heilmann book", "a robert e. heitmann book"
"a robert j. heilman book" » "gal robert j. heilman book", "a robert _. heilman book", "a robert j. heilmann book", "a robert j. heitmann book"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("a robert e. heilman book") or ("a robert j. heilman book"))) or ("a robust _. hellman book"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("a robert e. heilman book") OR ("a robert j. heilman book"))) OR ("a robust _. hellman book")).
• Removing quotes may allow a broader search: (((( a robert e. heilman book ) or ( a robert j. heilman book ))) or ( a robust _. hellman book )).
• Adding a wildcard symbol may retrieve word variants: (((("a robert e. heilman book") or ("a robert j. heilman book"))) or ("a robust _. hellman book"))*.